The Threats
Butcher of the Horde and Goblin Rabblemaster are the centerpieces of this deck, and Stormbreath Dragon and Sarkhan, the Dragonspeaker serve as additional finishers. Seeker of the Way is here as a way to apply some early pressure as well as regain some life against aggressive decks.
The Support
I was initially a little worried that Hordeling Outburst was low on power level, but it works well with both Rabblemaster and Butcher as well as Sorin, Solemn Visitor. Sorin pushes through extra damage and also adds a threat when played onto an empty board. I'd love to find room for another Chandra, Pyromaster, but the four-drop slot is rather glutted right now. She's a source of card advantage and her ability to stop something like Courser of Kruphix from blocking can be very useful.
The Answers
Crackling Doom is this deck's main answer to big threats like Siege Rhino and Sarkhan, the Dragonspeaker, supplemented with a miser's Utter End for utility. Lightning Strike and Stoke the Flames are here to handle premier three-drops like Mantis Rider and Goblin Rabblemaster, among other things...it's also nice just to be able to go to the face after getting in a hit or two with a Rabblemaster or Butcher.
The Sideboard
Anger of the Gods is here for the aggressive decks--I recently made the switch from Arc Lightning as I'm generally boarding out Goblin Rabblemaster against aggressive decks anyway. Brimaz, King of Oreskos comes in against just about anything as a resilient threat. End Hostilities comes in against Green Devotion and Abzan. Glare of Heresy is useful against the two top decks of the format, Jeskai and Abzan, and Erase has high-priority targets in many matchups. Finally, Purphoros, God of the Forge comes in as a resilient threat against control decks while Outpost Siege can help me stay in attrition-based matchups. Duress can help me force a threat through against control.
Mardu Charm and Chained to the Rocks are the two biggest considerations. The Charm is versatile but competing with a lot in the three slot, while Chained is efficient but attackable (chaining a Siege Rhino makes me a little nervous). I'm also considering trying to find room for another Stormbreath Dragon (I like it better than Sarkhan because protection from white is very relevant vs. Abzan and Jeskai). Thoughtseize has been removed because I decided to make White the secondary color rather than Black, and I'd rather be deploying threats to the board.
